Collect viewed objects in visualization methods

When rendering any given page there is currently no way to know what objects is used on the page. Knowing this opens easier debug options as you can provide a list with edit links to every object on the page, and it gives you a better overview of how the implementation is built up.

It would be low overhead to collect the object/version ids every time on of the visualization methods run

node_view_gui

content_view_gui

content_version_view_gui

This list could then be provided in a PHP API as well as a fetch function. If the fetch function / API is used before every node is rendered, then only those rendered up-to that point should be included.